Offset rotary copying machine



May 9, 1939. 1.. KLUlTMANN OFFSET ROTARY COPYING MACHINE Filed July 21, 1937 Patented May 9, 1939 UNITED STATES PATENT OFFICE OFFSET ROTARY COPYING MACHINE Leo Kluitmann, Dusseldorf, Germany Application July 21, 1937, SerialNo. 154,894 In Germany July 24, 1936 7 Claims. (Cl. 101-144) By the patent application Serial No. 549,867, during the printing process by a brush cylinder filed July 10, 1931, a rotary copying machine with or the like, preferably rotating in a direction a copyable original in mirror script fixed on a opposite to that of the rubber cylinder, said brush printing drum for printing moistened sheets has cylinder being arranged between the printing become known, in which the original in mirror point and that point on which the intermediate 5 script fixed on the printing cylinder is auto-' print is transmitted onto the rubber cylinder. matically changed without stopping of the print- In offset rotation copying machines it becomes ing drum, in that for instance grippers which therefor necessary for the first time to provide an securely hold the original on the printing cylinder ink removing and cleaning device for the trans- 10 are automatically opened, a fresh original lying mitting roller. In this manner it has to be made 10 for instance on a table being automatically fed possible to employ also in offset copying machines to the grippers whereupon the grippers close and the original exchanging device according to the securely hold the fresh original. prior specification.

The invention opens a new range of application Only by the invention it is attained that after for the device for changing originals described the original has been changed the fresh original 15 and claimed in the prior specification, and acis immediately printed perfectly. The invention cording to the invention the device for changing may however be carried out in such a manner .the original as disclosed by the prior application that two transfer cylinders (rubber cylinders) is employed in offset rotation copying machines are provided which are controlled automatically with an original fixed on a printing cylinder. in dependency on the change of original in such 20 If the printing original changing device known a manner that actually the one cylinder is emper se is used in offset rotary duplicating maployed for the printing whilst the other cylinder chines, there is provided according to the invenis being cleaned.- Also in this instance the cleantion for the transfer cylinder (rubber cylinder) ing of the cylinder can be carried out by brush an automatic ink removing and cleaning device, cylinders or the like rotated in a direction op- 25 which cleans the circumferential surface of the p'osite to the cylinder to be cleaned. transfer cylinder before beginning to print with By the invention it is therefore rendered the fresh printing original so that after changing possible to employ the automatic changing of the printing original, the fresh printing original original without stopping of the machine also in is immediately printed perfectly on the sheets or ofiset rotation copiers and to thereby make these 30 the like. machines work economically also for smaller The originals have been fixed in this machine editions.

up to the present by means of perforations and An offset-rotation copying apparatus is shown pins on the printing cylinder and by hand. If in the accompanying drawing, by way of example,

an original had to be changed, it was necessary in which two rubber cylinders are provided. 5 to detach the original by hand from the pins and Fig. 1 shows a side elevation of the copying besides to clean the transfer cylinder, in order apparatus, and that after the insertion of the fresh original only Fig. 2 a front view of the same. the ink transferred from the fresh original upon In the machine shown in the drawing the cylint et ns e y nde e t s tted upon t der I carries the original. The machine com- 40 sheet to be printed. The changing of an original prises further two transfer cylinders (rubber demands therefor in the offset rotation copiers cylinders) 2 and 2a, and an impression cylinder of known type very much time and requires every 3 which presses the paper sheet 35 to be printed timeastopping of the machine. against the rubber cylinder 2, 2a respectively.

The invention offers in comparison with the The cylinder 3 is journalled in bearings 8 which 45 known off r ti n py machines h great are guided in the machine frame 39 and pressed advantage that in economical manner in shortest in upward direction by springs 9. The transfer time even small numbers of copies can be procylin ders 2 and 2a are journalled in bearings 5 duced. The changing of original is effected acguided in two guide bars 4 and pressed by springs cording to this invention absolutely automatically 6 in upward direction against the cylinder I. The 50 without stopping of the printing machine. guide bars 4 can be brought on their beds 38 into The invention can be carried out in different two different positions so that, in the one position manners. The arrangement may be for instance the one rubber cylinder and in the other position such that the transfer cylinder (rubber cylinthe other rubber cylinder is in the operative posider) is continuously freed from ink and cleaned tion necessary for the printing. In both these 55 positions the guide bars 4 are secured in their position by stopping balls I pressed on by means of springs. Felt pads l filled with a suitable liquid for cleaning the transfer cylinder which is actually not employed for printing are provided. These felt pads may either be pressed against the cylinder by hand by the operator of the machine or by spring pressure. The twcftransfer cylinders .2 and 2a are coupled by a chainor wedge belt drive 31, so that the cylinder not actually employed for printing is rotated by the cylinder actually in working position and cleaned by the corresponding felt pad ID. 'The inking mechanism is shown generally at H which may be of any well known construction and include an inking roller l2 adapted to engage the cylinder I.

Two double armed levers l3 serve for controlling the guide bars 4, one arm of said levers having a slot engaging over a stud |3a of the guide bars 4, said levers being mounted on the axle M of the printing cylinder. The two other arms of the levers l3 have slots of a special shape, said slots engaging over pins l6 of the control cranks I5. These control cranks l5 are keyed on the axle ll, on which a spur wheel I8 is mounted axially shiftable but not turnable. This spur wheel l8 can be brought by axial shifting into engagement with a toothed segment l9 fixed on the cylinder I. Normally, the spur wheel I8 is kept out of gear by a spring l8b mounted on the axle l1 and supported by a collar 18a. Owing to the slots 40 engaging over the pins I6 of the cranks l5 it is ensured that, during a semi-rotation of the cranks, the rubber cylinder 2 which is in the operative position is brought into the cleaning position and that simultaneously the rubber cylinder 2a being in the cleaning position is brought into the operative position.

The arrangement is such, that the devices employed for controlling the mechanism for changing the original serve at the same time for bringing the spur wheel l8 serving for altering the position of the rubber cylinder into gear with the toothed segment l9.

In the copying machine of known type a carriage 20 with a curve 29 is lifted by depressing of a lever 2!, the table plate 30 being lowered at the same time and brought into the range of catches provided on the printing cylinder, grippers 42 mounted on an axle 26 being at the same time opened by the upward movement of a roller 43 fixed on lever 21. In the copying machine according to the invention the carriage 20 has at its upper portion an inclined surface 23 designed to influence a roller 24a mounted at the end of lever 24. This lever 24 is oscillatably mounted in a' bracket 25 on frame 39 of the machine. By actuating the handle 2!, the carriage 20 is lifted, the inclined surface 23 presses in side ward direction the roller on the lever 24 and thereby shifts the spur wheel 18 over a wedge on the axle ll into its engaging position.

The paper to be printed is introduced by hand or in known manner automatically from a pile 35 to between the pressing on cylinder 3 and the rubber cylinder 2 and laid after the printing onto the table plate 36.

The operation of the arrangement described is as follows:-- i

If the original has to be changed, the lever 2i, pivotally mounted on the fulcrum 4 i is depressed, and thereby the carriage 20 is lifted. If, during the rotation of the cylinder l, the crank 2'! of the crank shaft 26 comes into the range of the curve 29, the grippers 42 are opened and the clamped original is released. The released original falls upon a delivery table (not shown) arranged parallel to the table 30 at the height of the tangential plane of the cylinders l and 2. At the same time the front portion of table 30 is lowered relative to the printing cylinder and the new original is fed to the grippers in known manner. At this moment the printing from the original already liberated by the grippers is not yet completely finished so that it is necessary to maintain in operation the rubber cylinder 2, which is in its operative position, until the printing from the original has been completed. Whereas the two rubber cylinders 2 and 2a still remain in their previous position, the new original is gripped by the grippers and drawn along by the printing cylinder I. At the moment at which the printing from the original to be removed has been completed, the two rubber cylinders 2 and 2a must be brought into the second position. The toothed segment I9 is therefore arranged on the cylinder l displaced by such an angle relative to the gripper shaft 26, that accurately at this moment the shifting of the rubber cylinders takes place. The ratio of transmission between the toothed segment I 9 and the spur wheel I 8 and the length of the toothed segment l9 are selected so that, when the two parts come into gear, the spur wheel I8 is rotated by one half-rotation, and so that this semi-rotation has already been completed, when the upper end of the fresh original .comes into the range of the rubber cylinder 2.

During the half rotation of the spur wheel l8 the shaft l1 and also the two control cranks I5 keyed on this shaft are turned by 180. During the rotating of the cranks IS the studs [6 engaging into the slots 40 of the levers l3 cause an oscillation of the double-armed levers l3 and thereby the desired shifting of the rubber cylinders 2 and 20. As the rubber cylinder 2 or 2a respectively, which has just been shifted into the operative position, has previously been in the cleaning position, it is perfectly freed from ink and can now be employed for printing from the fresh original. The rubber cylinder 2, which has just been employed for the printing, is now in the cleaning position and is freed from ink and cleaned by the felt pad Ill saturated with a cleaning liquid. After the hand lever 2! has been liberated, it descends under the action of spring 22 again into the initial position, the carriage 20 and the inclined surface 23 being also lowered again, so that, under the action of spring l8b, also the spur wheel l8 returns into the normal position.

The curve-like construction of the slots 40 is necessary in order to make it possible that the cranks It: with the rollers l6, during the turning in the lower semicircle, can freely pass through in the first and last third. If the slots were parallel, the cranks i5 with the roller l6 would effect in the lower semicircle in the first third at about and in the last third at about 135, abnormal movement of the carriages 4 and the cylinders 2 and 20. mounted thereon.

I claim:-

1. In an offset copying machine, a printing cylinder, means for securing a foil on the printing cylinder, an offset cylinder, the combination of means operatively connected to the printing cylinder for moving the offset cylinder into and out of active position with respect to the printing cylinder, with means for cleaning the offset cylinder when it is in inactive position.

2. In an ofisetcopying machine, a printing cylinder, means for securing a foil on the printing cylinder, a pair of offset cylinders, means operatively connected to the printing cylinder for alternately moving one of the offset cylinders into active position ,with respect to the printing cylinder, and means for cleaning that offset cylinder which is in inactive position at the time.

3. In an offset copying machine, a frame, a printing cylinder, a slide mounted for reciprocation in the frame, a pair of offset cylinders mounted on the slide, means operatively connected to the printing cylinder for shifting the slide for alternately moving one of the ofiset cylinders into active position with respect to the printing cylinder, and means for cleaning that offset cylinder which is in inactive position at the time.

4. In an offset copying machine, a frame, a printing cylinder, a slide mounted for reciprocation in the frame, a pair of offset cylinders mounted on the slide, a crank operatively connected to the printing cylinder, a double-armed lever having a cam slot adapted to be engaged by the crank in one of its arms and operatively connected to the slide with its other arm for shifting the slide for alternately moving one of the offset cylinders into active position with respect to the printing cylinder, and means for cleaning that offset cylinder which is in inactive position at the time.

5. In an ofiset copying machine, a frame, a printing cylinder, a slide mounted for reciprocation in the frame, a pair of ofiset cylinders mounted on the slide. a crank, a clutch operatively connecting the crank to the printing cylinder, manually operated means for controlling the clutch, a double-armed lever having a cam slot adapted to be engaged by the crank in one of its arms and operatively connected to the slide with its other arm for shifting the slide for alternately moving one of the offset cylinders into active position with respect to the printing cylinder, and means for cleaning that ofiset cylinder which is in inactive position at the time.

6. In an offset copying machine, a frame, a printing cylinder, a slide mounted for reciprocation in the frame, a pair of offset cylinders mounted on the slide, a crank shaft, a pinion splined on the crank shaft, a toothed sector on the printing cylinder whose length is equal to one-half of the pinions perimeter, manually operated means for shifting the pinion into mesh with the sector, a crank on the crank shaft, a double-armed lever having a cam slot adapted to be engaged by the crank in one of its arms and operatively connected to the slide with its other arm for shifting the slide for alternately moving one of the offset cylinders, into active position with respect to the printing cylinder, and means for cleaning that offset cylinder which is in inactive position at the time.

7. In an offset copying machine, a frame, a printing cylinder, a slide mounted for reciprocation in the frame, a pair of ofiset cylinders mounted on the slide, a crank shaft, a pinion splined on the crank shaft, a toothed sector on the printing cylinder whose length is equal to one-half of the pinions perimeter, manually operated means including a slide and a cam on the slide for shifting the pinion into mesh with the sector, a crank on the crank shaft, a doublearmed lever having a cam slot adapted to be engaged by the crank in one of its arms and operatively ,connected to the slide with its other arm for shifting the slide for alternately moving one of the ofiset cylinders into active position with respect to the printing cylinder, and means for cleaning that oflset cylinder which is in inactive position at the time.

LEO LUn'MANN. 

